Anthropic's Claude Mythos model found new cryptographic weaknesses

Anthropic says its Claude Mythos Preview model discovered weaknesses in cryptographic algorithms that secure the internet, including an improved attack on HAWK, a post-quantum signature scheme human experts had reviewed for over two years. The model found the weakness in about 60 hours at an estimated API cost of $100,000. Anthropic says the findings don't affect systems currently in use.

Why it matters: This shows a frontier model producing genuinely novel cryptanalysis that professional cryptographers missed for years, not just summarizing known security research — a real capability jump with dual-use implications, since the skill that finds flaws to fix them could also find flaws to exploit. Coming the same week as the OpenAI/Hugging Face agent intrusion story, it adds weight to the safety statements above: offensive and security-relevant AI capabilities appear to be advancing faster than institutions have adjusted for.